A shit umbrella is great to have if the alternative is a shit funnel. But how are you gonna appreciate the shit umbrella if it's pitch black, blocks everything at all times?

You're not gonna appreciate it. In fact, you might think some of the things your manager does are the "bad things", when in fact, it's just the umbrella bowing under all the shitload.

If the umbrella is (somewhat) transparent, you, as the manager, gain some legitimacy through transparency. You're no longer the manager that "sits around on his ass all day doing nothing". You're actually doing something for the team and they can "see" it, even though it doesn't affect them.